The invention relates to electrical connectors used in mass termination arrays, and more particularly to wire terminal connectors employed in utility interface equipment.
To provide an efficient telephone distribution system between a central telephone equipment office and individual subscribers, primary distribution cables, called "feeder" cables, with as many as three thousand wire pairs must be connected to secondary distribution cables typically three hundred to nine hundred wire pairs apiece, usually at a location remote from the central office. This requires equipment with a capability for terminating and interconnecting a large number of wires.
In general, large numbers of wire connections are made to cross-connecting terminal blocks and wiring panels. In these devices, wires from feeder cables and secondary distribution cables are terminated on one side of the terminal block or panel, and cross-connections between the cables are made with jumper wires on the opposite side of the terminal block or panel.
In A. J. Humphries, U.S. Pat. No. 2,450,001, a cross-connection strip is shown, in which a pair of wires may be connected to a terminal, according to the specification, "through the medium of a single screw." The screw in Humphries' cross-connection strip has a point contact against a pressure block. The wires are each inserted between the pressure block of insulating material and a contact plate. Each terminal, including a pressure block and two contact plates is housed in a terminal block of honeycomb configuration. Substantial improvements over this type of cross-connection strip in the arrangement of screw fasteners, the design and operation of contacts, assembly requirements, and adaptability to mass termination and testing equipment, can be realized in a terminal module with binding post terminals.
Binding post terminals, which have been used in many other fields, have sometimes been used in cross-connect interface equipment. A wire can be secured in such a terminal by advancing a screw with an ordinary screwdriver. The binding posts of the prior art have been used most commonly to connect wires within a single circuit, whether one or more wires have been connected. See, for example, Christiansen, U.S. Pat. No. 3,555,495; Chryst, U.S. Pat. No. 1,193,513; and Munsie, U.S. Pat. No. 426,204. In telephone equipment it is necessary that wires be connected in pairs to other pairs of wires, Therefore, where it has been desired to use a binding post terminal in telephone interface or cross-connect equipment, wires have been connected in two ways. Two binding posts have been used to separately connect each wire in a pair. Or, a pair of contact points have been arranged coaxially on axially extending threaded members. With either of these constructions, the bare ends of the wires must be wrapped around the shaft of the screw or carefully held against a contact point until secured. This slows the basic jumping installation operation which is repeated thousands of times in cross-connecting or interfacing applications.